Roll mills



M y '7, 5 E. A. SCHWARZ 2,708,399

ROLL MILLS Filed Jan. 26, 1951 2 Sheets-Sheet l 02 50 rnysj.

y 1955 E. A. SCHWARZ 2,708,399

ROLL MILLS Filed Jan. 26, 1951 2 Sheets-Sheet 2 Gifowne ys.

2,798,399 Patented May 17, 1955 ROLL MILLS Eugene A. Schwarz, Snyder, N. Y., assignor to The Squier Corporation, a corporation of New York Application January 26, 1951, Serial No. 207,885 4 Claims. (Cl. 100-163) This invention relates to improvements in apparatus or roll mills for pressing materials such as sugar cane, tree bark and other materials, in which an upper roll is pressed against one or more lower rolls and between which rolls the material to be treated is passed.

In apparatus of this type, it sometimes happens that the supply of material to said rolls is not uniform so that a larger mass of material is conveyed at one time to the rolls than can be passed through the space between the rolls, thus damming up the supply of material passing to the mill. foreign body, such as a steel implement, a stone, or other rigid object which may be damaging to the rolls, may accidentally be on the conveyor conducting the material to the rolls.

One of the objects of this invention is to provide means for quickly relieving the pressure or force urging the upper roll downwardly, so that dammed up material may pass quickly between the rolls, and so that if a foreign body passes between the rolls, damage to the rolls will be avoided or decreased. It is also an object of this invention to provide an improved roll mill equipped with means for relieving the pressure forcing the upper roll toward the lower roll and simultaneously applying force to the upper roll to raise the same from the lower roll or rolls. Another object of this invention is to provide means operated by fluid pressure for rapidly raising the upper roll. A further object is to provide a mounting for the upper roll which permits the same to be quickly raised.

Another object is to provide means for quickly raising the upper roll to permit the passage of material between the same without damage to the roll and by means of which the upper roll can be quickly restored to its operative position, either while the mill is at rest or while the rolls are rotating.

Other objects and advantages will be apparent from the following description of one embodiment of the invention and the novel features will be particularly pointed out hereinafter in connection with the appended claims.

In the accompanying drawings:

Fig. 1 is a side elevation of a roll mill comprising upper and lower rolls and provided with means embodying this invention whereby the upper roll may be quickly raised and quickly restored to its operating position.

Fig. 2 is a diagrammatic view showing the connections by means of which fluid pressure to various parts of the mill may be controlled for moving the upper roll up wardly with relation to the lower rolls and whereby the upper roll may be quickly restored to its working position.

Fig. 3 is a fragmentary sectional elevation of one of the housings of the mill shown in Fig. 1, the section being taken approximately on line 3-3, Fig. 1.

Fig. 4 is a similar section showing a modified construction for use in connection with raising the upper roll.

It also sometimes happens that a Fig. 5 is an end elevation of the mechanism shown in Fig. 4.

In the accompanying drawings, the improvements embodying this invention are illustrated by way of example as they may be used in connection with a three roll mill of the type commonly employed for express ing juice from sugar cane. In Fig. 1 of the drawings, the mill comprises an upper mill roll 10 and two lower rolls 11 and 12 which are connected by suitable gearing (not shown) so that the three rolls will be driven at the same peripheral speeds in directions to advance the material to be pressed through the mill from one end thereof to the other. The rolls are provided with roll shafts extending beyond the opposite ends thereof and these shafts are rotatably mounted in suitable housings at opposite sides of the mill, the housings shown being provided with an upper housing member 14 suitably mounted on and secured to a lower housing member 15. Two roll shafts 17 and 18 for the lower rolls are journalled in suitable bearings 19 and 20 mounted in the lower housing member 15 and the upper roll shaft 21 is journalled in a bearing which, in the particular construction, includes a lower bearing member 22 and an upper bearing member 24, these bearing members being slidable vertically in suitable guideways in the upper housing member 14. The upper bearing parts 24 for the upper roll are pressed downwardly toward the lower rolls by any usual or suitable hydraulic mechanisms 25, each of which includes a piston or plunger 26 arranged in a cylinder 27. The pistons 26 exert a yielding pressure against the upper bearing parts 24, and thus force the upper roll toward the lower rolls. The rolls may be provided with the usual annular grooves and ridges arranged so that the ridges of the upper roll will enter into the grooves of the ridges of the lower rolls. The usual turnplate may be provided for feeding material from the bight between the upper roll and one of the lower rolls into the bight between the upper roll and the other lower roll, this turnplate being omitted from the drawings for sakeof clarity. The turnplate may be adjusted relatively to the rolls by means of an arm 28 which may be adjusted by screw-threaded rods 29 pivoted to the arm 28 and provided with nuts bearing against lugs formed on the lower housing member 15.

Material to be treated may be fed to the mill in any suitable or desired manner, and since such feeding means are commonly used with mills of this type they are not herein shown. Such feeding means may, for example, include a conveyor upon which the material to be acted on by the mill is placed. Preferably the layer of material on such conveyor is arranged in a layer of substantially uniform thickness, but it occasionally happens that the layer on the conveying apparatus differs in thickness so that at intervals a portion of the layer may be of such thickness that it will not enter between the rolls. When this occurs the material in the con veyor is more or less dammed up on the conveyor, thus temporarily stopping the operation of the mill and piling up a mass of material at the entrance to the mill.

With mills of this type as heretofore constructed, this necessitated stopping the mill and then removing excess material from the conveyor, which was time-consuming and interfered with the production of the mill.

It also happens occasionally that a foreign object, such as a stone, a metal tool, or other implement passes along the conveyor to the mill and such obj ct may seriously damage the rolls and the turnplate, which might necessitate a shut-down of the mill. It is, therefore, necessary for the efiicient operation of the mill and to pr vent damage to the mill and to provide means for quickly relieving the pressure on the upper roll so that the dammed up material may be passed through the mill and so that a foreign object conveyed to the mill may pass through the mill without damaging the rolls or turnplate.

In order to prevent such shut-downs and damage to the mill, I have provided suitable means which may be quickly actuated by an operator to relieve the pressure acting on the piston 26. Since machines of this type may be very large in size so that merely relieving the pressure on the upper roll may not be sufficient to permit the material entering the mill to raise the upper roll because of its weight, I have also provided means for lifting the upper roll to permit material to pass between the rolls without being pressed, so that an excessively large mass of material may pass through the mill and so that foreign objects may pass through the mill without damaging any of the parts thereof, or at least greatly reducing the damage which would result if the rolls had not been separated.

In the constructions shown, the m ans for raising the upper roll includes a pair of fluid pressure operated devices, one for each housing, such for example as hydraulic jacks, each including a cylinder and a piston. In the constructions shown in Figs. 1 to 5, the pressure controlled members are mounted on the lower housing members, which as shown in Fig. 1, are provided with an integral upwardly extending part a on which the lower bearing member 22 rests when in its lowest position.

In the embodiment of this invention shown in Figs. 1 and 3 each of these fluid pressure actuated devices may, for example, include a cylinder 36 in which a piston 31 operates, these cylinders being arranged within hollow portions or cavities 32 in the parts 15a of the lower housing members 15. These parts of the lower housin members are preferably provided with suitable slide members or cylinders 33 mounted in guides or sleeves 34 suitably secured in the parts 15a of the housing members 15. The upper ends of the slide members or cylinders 33 are mounted to bear against the lower bearing members 22 for the upper roll shaft 21. Each of the hydraulic cylinders 36 is seated on a transverse web 35 of the housing member 15 and is connected with a tube or conduit 36 for conducting fluid pressure to the cylinder 39 and when this fluid under pressure is supplied to the cylinder, the piston 31 thereof will move upwardly, for example, into the dot-dash line position shown in Fig. 3 and carry the slidable cylinder 33 and the lower bearing part 22 upwardly to the same extent. Generally the upward movement of the upper roll required to clear the mill and prevent damage thereto is not very great. An inch and one-half upward movement, for example, being generally sufficient for this purpose, but the extent of this movement may vary considerably, depending on the size of the roll mill and upon other conditions. The outer walls of the parts 15a of the lower housing members may be provided with openings 37 through which the fluid pressure operated devices or hydraulic jacks may be inserted into the cavities 32, or removed therefrom. These jacks may be provided with bases 38 which seat on the transverse webs 3d and may be secured in place in any desired manner, for example, by screws 39.

In Fig. 2, I have shown diagrammatically an arrangement of pipe connections and a three-way valve by means of which the relieving of pressure on the hydraulic cylinder 27 and the application of pressure to the lifting cylinders 30 may be instantly effected. In Fig. 2, are shown two devices do and 41 for producing the high fluid pressure ordinarily used on mills of this type, and since these pressure producing devices are well known in the art, they are in Fig. 2 illustrated merely diagrammatically. Each of these pressure producing devices includes a relatively large piston arranged in a cylinder 42 and connected with a small piston arranged in the cylinder 43. Air pressure is usually applied to the large cylinders 42 to move the small pistons in the cylinders 43, so that a high hydraulic pressure may be developed in the cylinders 43 by use of a materially lower air pressure in the larger cylinders 42, as will be readily understood. In Fig. 2, air pressure is passed through tubes 44 and 45 to the large cylinders 42. The oil or other hydraulic fluid under high pressure from the small cylinder 43 of the pressure producing device 40 passes through conduit 47 to the two cylinders 27 which produce the downward pressure on the upper roll it). The hydraulic pressure line or conduit 36 connected to the two pistons 36 of the hydraulic lifting jacks is also connected to the small cylinder 43 of the other pressure producing device 41. The numeral 4-9 represents a conduit from a supply of air or other gas under pressure leading to a valve 5 This valve has a pair of passages or ports 51 and 52 and the valve is shown in Fig. 2 in a position to relieve pressure on the cylinders 27 and apply pressure to the cylinders 36 of the lifting jacks. It will be noted that when the valve is in the position shown in Fig. 2, air under pressure is supplied to the cylinder 42 of the pressure producing mechanism 41 which supplies pressure to the lifting jacks, and air is discharged from the cylinder 42 of the pressure producing device 40 through the passage 51 of the valve 5% and through an air discharge passage 53. When the valve member is turned through degrees in either direction from the position shown in Fig. 2, one of the valve ports will connect the air supply pipe 49 with the conduit 44 leading to the pressure producing device All and the other valve port will then connect the conduit 45 with an air discharge passage 53. It will thus be obvious that when an occasion arises for lifting the upper roll Ill, it is merely necessary for an attendant to turn the movable valve member 50 through a quarter of a turn, and as soon as the necessity for lifting the upper roll has passed, the valve can be again turned to its initial position to render the lifting jacks inoperative and to apply pressure to the upper roll.

In Figs. 4 and 5, I have shown a modified form of my invention in which the lifting jacks are secured to a side of each lower housing member 15. In this construction, a bracket 6% for supporting the lifting jack is applied to each housing member 15, for example, by means of belts or screws 61. Each bracket is provided with a pair of outwardly extending webs or flanges 62 spaced apart and formed to receive between them a hydraulic jack including a cylinder 63 and a piston 64. In the construction shown, the cylinder 63 is provided with a pair of outwardly extending trunnions 66 which are formed to seat inapproximately semi-circular recesses 67 formed on the upper edges of the flanges 62. Lower trunnions 68 are also provided on the hydraulic jack which enter loosely into recesses 69 in the lower portions of the flanges 62.

The piston 64 of each hydraulic jack cooperates'with an enlarged head '76 arranged in a recessed portion 71 of an outwardly extending flange 72 of the frame member 15. The upper surface of the enlarged head is formed to engage the lower bearing portion 22 of the upper roll. Consequently, when fluid under pressure is admitted to the cylinders 63 through the conduit or tube 36, the heads 7i) will move upwardly into engagement with the ends of the bearing parts 22 and raise the upper roll 10. It will be understood that the enlarged heads 7% may, if desired, be formed to engage the upper roll shafts 21 directly in the event that the bearings 22 do not extend outwardly sufiiciently far to enable the heads 79 to engage these bearings. The hydraulic jacks shown in Figs. 4 and 5 may be actuated by the same mechanism illustrated in Fig. 2.

It will be understood that various changes in the details, materials and arrangements of parts which have been herein described and illustrated in order to explain the nature of the invention may be made by those skilled in the art within the principle and scope of the invention as expressed in the appended claims.

I claim:

1. In a three-roll mill having an upper and two lower rolls provided with roll shafts extending beyond the ends thereof and having the axes of the roll shafts in triangular arrangement, bearings for said roll shafts cooperating with the end portions of said roll shafts, housings for said mill on which said bearings are supported and in which the upper roll bearings are slidably mounted to permit said upper roll to move toward and from said lower rolls, and fluid pressure operated members located above and acting on said bearings of said upper roll for urging said upper roll downwardly toward said lower rolls, that improvement which includes a pair of fluid pressure operated jacks mounted on said housings underneath the end portions of the shaft of said upper roll and in a plane extending between the shafts of said lower rolls, and acting on said bearings of said upper roll in a direction to raise the same when supplied with fluid under pressure, a source of high pressure fluid, conduits connecting said source with said pair of fluid operated members, other conduits connecting said source with said jacks, and means for simultaneously discharging high pressure fluid from said fluid pressure operated members and admitting high pressure fluid to said jacks, for quickly lifting said upper roll clear of said lower rolls.

2. In a three-roll mill having an upper and two lower rolls provided with roll shafts extending beyond the ends thereof and having the axes of the roll shafts in triangular arrangement, bearings for said roll shafts cooperating with the end portions of said roll shafts, housings for said mill on which said bearings are supported and in which the upper roll bearings are slidably mounted to permit said upper roll to move toward and from said lower rolls, and fluid pressure operated members located above and acting on said bearings of said upper roll for urging said upper roll downwardly toward said lower rolls, that improvement which includes a pair of fluid pressure operated jacks mounted on said housings underneath the end portions of the shafts of said upper roll and in a plane extending between the shafts of said lower rolls, and acting on said bearings of said upper roll in a direction to raise the same when supplied with fluid under pressure, a pair of devices for producing a fluid at high pressure from another fluid at low pressure, conduits connecting high pressure fluid from one of said devices to said pressure operated members, and other conduits connecting the high pressure fluid from the other of said devices to said pressure operated jacks, conduits for conducting low pressure fluid to each of said pressure producing devices, and a valve in said last mentioned conduits for admitting low pressure fluid to either of said devices and for simultaneously discharging low pressure fluid from the other of said devices.

3. In a three-roll mill having an upper and two lower rolls provided with roll shafts extending beyond the ends thereof and having the axes of the roll shafts in triangular arrangement, bearings for said roll shafts cooperating with the end portions of said roll shafts, a pair of housings for said mill on which said bearings are supported, each of said housings including upper and lower housing members, said lower housing members supporting bearings for said lower rolls and having upwardly extending parts extending upwardly between the bearings for said lower roll and on which the bearings for said upper roll are supported when in their lowest positions, said upper housing member including guides in which said bearings for said upper roll slide toward and from said lower rolls, and fluid pressure operated members acting on said bearings of said upper roll for urging said upper roll downwardly toward said lower rolls, that improvement in which said upwardly extending parts are hollow, a fluid pressure operated jack mounted in each of the hollow portions of said housings underneath the bearings of the shaft of the upper roll, and slide members guided for vertical movement on said lower housing members and interposed between said jacks and the bearings for said upper roll, a source of high pressure fluid, conduits connecting said source with said pair of fluid operated members, other conduits connecting said source with said acks, and means for simultaneously discharging high pressure fluid from said fluid pressure operated members and admitting high pressure fluid to said jacks, for quickly lifting said upper roll clear of said lower rolls.

4. In a three-roll mill having an upper and two lower rolls provided with roll shafts extending beyond the ends thereof and having the axes of the roll shafts in triangular arrangement, bearings for said roll shafts cooperating with the end portions of said roll shafts, a pair of housings for said mill on which said bearings are supported, each of said housings including upper and lower housing members, said lower housing members supporting bearings for said lower rolls and having upwardly extending parts extending upwardly between the bearings for said lower roll and on which the bearings for said upper roll are supported when in their lowest positions, said upper housing member including guides in which said bearings for said upper roll slide toward and from said lower rolls, and fluid pressure operated members acting on said bearings of said upper roll for urging said upper roll downwardly toward said lower rolls, that improvement which includes brackets mounted on said upwardly extending parts of said lower housing members, fluid pressure operated jacks mounted on said brackets underneath the bearings for the shaft of the upper roll, a source of high pressure fluid, conduits connecting said source with said pair of fluid operated members, other conduits connecting said source with said jacks, and means for simultaneously discharging high pressure fluid from said fluid pressure operated members and admitting high pressure fluid to said jacks, for quickly lifting said upper roll clear of said lower rolls.

References Cited in the file of this patent UNITED STATES PATENTS 497,301 Buchel May 16, 1893 844,350 Hale Feb. 19, 1907 1,124,643 Ogg Jan. 12, 1915 1,810,102 Faber June 16, 1931 2,204,434 Munson June 11, 1940 2,205,632 Schwartz June 25, 1940 2,281,294 Malkin Apr. 28, 1942 FOREIGN PATENTS 435,367 Great Britain Sept. 19, 1935 

